From patchwork Fri Mar 4 09:34:07 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Miaohe Lin X-Patchwork-Id: 12768818 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 753C0C433EF for ; Fri, 4 Mar 2022 09:35:33 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 39DFC8D0011; Fri, 4 Mar 2022 04:35:14 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 3000F8D0005; Fri, 4 Mar 2022 04:35:14 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 216DF8D0011; Fri, 4 Mar 2022 04:35:14 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.hostedemail.com [64.99.140.27]) by kanga.kvack.org (Postfix) with ESMTP id 099528D0005 for ; Fri, 4 Mar 2022 04:35:14 -0500 (EST) Received: from smtpin03.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay13.hostedemail.com (Postfix) with ESMTP id D11F560A60 for ; Fri, 4 Mar 2022 09:35:13 +0000 (UTC) X-FDA: 79206195306.03.0BCB7F5 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by imf05.hostedemail.com (Postfix) with ESMTP id 25F7610000B for ; Fri, 4 Mar 2022 09:35:12 +0000 (UTC) Received: from canpemm500002.china.huawei.com (unknown [172.30.72.57]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4K92jW6Nn2zdgC7; Fri, 4 Mar 2022 17:33:51 +0800 (CST) Received: from huawei.com (10.175.124.27) by canpemm500002.china.huawei.com (7.192.104.244) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.21; Fri, 4 Mar 2022 17:35:09 +0800 From: Miaohe Lin To: CC: , , , , , , , , , , , , , , , , , , Subject: [PATCH 14/16] mm/migration: fix potential invalid node access for reclaim-based migration Date: Fri, 4 Mar 2022 17:34:07 +0800 Message-ID: <20220304093409.25829-15-linmiaohe@huawei.com> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20220304093409.25829-1-linmiaohe@huawei.com> References: <20220304093409.25829-1-linmiaohe@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.124.27] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To canpemm500002.china.huawei.com (7.192.104.244) X-CFilter-Loop: Reflected X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 25F7610000B X-Stat-Signature: iwbifmyy39rk591x8knhz4akhjcgtw1f Authentication-Results: imf05.hostedemail.com; dkim=none; dmarc=pass (policy=quarantine) header.from=huawei.com; spf=pass (imf05.hostedemail.com: domain of linmiaohe@huawei.com designates 45.249.212.188 as permitted sender) smtp.mailfrom=linmiaohe@huawei.com X-Rspam-User: X-HE-Tag: 1646386512-842467 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: If we failed to setup hotplug state callbacks for mm/demotion:online in some corner cases, node_demotion will be left uninitialized. Invalid node might be returned from the next_demotion_node() when doing reclaim-based migration. Use kcalloc to allocate node_demotion to fix the issue. Fixes: ac16ec835314 ("mm: migrate: support multiple target nodes demotion") Signed-off-by: Miaohe Lin Reviewed-by: "Huang, Ying" --- mm/migrate.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/mm/migrate.c b/mm/migrate.c index 279940c0c064..7b1c0b988234 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -2516,9 +2516,9 @@ static int __init migrate_on_reclaim_init(void) { int ret; - node_demotion = kmalloc_array(nr_node_ids, - sizeof(struct demotion_nodes), - GFP_KERNEL); + node_demotion = kcalloc(nr_node_ids, + sizeof(struct demotion_nodes), + GFP_KERNEL); WARN_ON(!node_demotion); ret = cpuhp_setup_state_nocalls(CPUHP_MM_DEMOTION_DEAD, "mm/demotion:offline",